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Vol. 32. Issue 2.
Pages 87-96 (April - June 2018)
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Vol. 32. Issue 2.
Pages 87-96 (April - June 2018)
Original article
DOI: 10.1016/j.ejpsy.2017.11.003
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A cross-sectional survey of psychotic symptoms in the community: The GRANAD∑P psychosis study
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M. Guerrero-Jiméneza, B. Gutiérrezb, I. Ruizc,d, M. Rodríguez-Barrancoc,d,e, I. Ibanez-Casasb, M. Perez-Garciaf, E. Valmisag, J. Carmonah, J.E. Muñoz-Negroa,b, J.A. Cervillaa,b,
Corresponding author
jcervilla@ugr.es

Corresponding author.
a Mental Health Unit, San Cecilio University Hospital, Granada, Spain
b Department of Psychiatry, Faculty of Medicine, University of Granada, Spain
c CIBERESP Centro de Investigación Biomédica en Red Epidemiología y Salud Pública, Spain
d Andalusian School of Public Health, Granada, Spain
e Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
f Faculty of Psychology, University of Granada, Spain
g Mental Health Unit, Puerto Real Hospital, Cádiz, Spain
h PISMA, Plan Integral de Salud Mental de Andalucía, Sevilla, Spain
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Figures (2)
Tables (3)
Table 1. Main previous cross-sectional studies prevalences of psychotic symptoms.
Table 2. Sample's sociodemographic and clinical characteristics.
Table 3. Positive answers to MINI psychotic symptoms subscale (prevalences/95% CI).
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Abstract
Background and objectives

Psychotic symptoms (PS) can be ascertained in the general population suggesting the existence of a wide psychosis phenotype. We aim to investigate the prevalence and correlates of PS in the province of Granada (Spain) in the absence of previous data. Our objectives were to establish the prevalence of PS, i.e. delusions and hallucinations, and identifying correlates with PS in search of plausible risk factors.

Methods

This is a cross-sectional study (GRANAD∑P study) including assessments of 809 individuals who were selected randomly from the Unified Database of the Andalusian Health System, a census covering about 98% of the entire regional population. PS were assessed by the MINI Neuropsychiatric International Interview Psychosis Subscale. A variety of potential risk factors for PS were also assessed including socio-demographics, cognitive function, psychiatric comorbidity and physical health issues.

Results

The prevalence of any PS in the province of Granada was 10.3% (hallucinations were detected in 6.1% of the sample and delusions in 7.4%). PS was correlated with increased suicide risk, lower functionality, having suffered childhood abuse, cannabis use, lower working memory and higher impulsivity.

Conclusions

The prevalence of PS in this Southern Spanish sample is similar to that found in other European populations. This may indicate that an extended subclinical psychotic phenotype can be detectable on general populations and that it associates to a variety of cognitive deficits, personality traits and environmental factors upon which we can direct preventative measures to prevent transition from subclinical non-cases to clinical cases states.

Keywords:
Epidemiology
Psychotic symptoms
Community
General population
Psychosis phenotype
Continuum of psychosis
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Introduction

Delusional and hallucinatory experiences have historically been defined as psychotic symptoms (PS). PS have been traditionally used clinically as a turning point for a diagnosis of psychotic disorder. However, a large body of literature shows now that PS can be ascertained in the general population among people who do not fulfil clinical criteria for psychotic disorder,1 thus suggesting a broader concept of a “wide psychosis phenotype”.2,3 Such notion has been supported by epidemiological, genetic, neuroimaging and clinical investigation findings.4 Hence, a kind of gradient would exist were healthy individuals without any psychotic experience would be situated at one end and those with a clinical psychosis would be at the other, being the latter “the visible tip of the iceberg”.4 Indeed, section II of DSM-V assumes this concept in some of its descriptions of psychosis.5 Few instruments have been validated to evaluate PS in community samples but the most commonly used instrument so far has been the Composited International Diagnosis Interview (CIDI) (PS section). Other studies have also used the Mini International Neuropsychiatric Interview that also contains its own PS section.6,7

Prevalence of psychotic symptoms in the general population

The occurrence of PS is not uncommon in non-clinical community samples. Thus, a recent meta-analysis suggests that PS in population based studies are about ten times higher than the prevalence of diagnosed psychotic disorders,8 estimating a median prevalence of 7.2% (4.9% hallucinations, 6.0% delusions). Among the most important studies included are the Dutch NEMESIS-I study2 reporting a prevalence of PS of 17.5% (8.2% for hallucinations and 12.2% for delusions), and the NEMESIS-II study reporting that 16% of participants exhibit some PS.9 Conversely, the British National Comorbidity Survey reported in 2004 a 5.5% PS prevalence in a British sample of 8850 individuals as measured with the Psychosis Screening Questionnaire (PSQ) (4.2% reported hallucinations and 9.1% delusions).10 In the United States, the National Comorbidity Survey reported 11.6% as PS prevalence (10.7% hallucinations, 2.2% delusions) in a sample of 5877 individuals using an expanded version of the CIDI.11 In addition, another cross-sectional study including 52 countries worldwide taking part in the World Health Organization's World Health Survey, reported more recently that the prevalence of having at least one PS ranged from 0.8% to 31.4%12 among participating countries. Other relevant recent studies have been the Singapore Mental Health Study (SMHS)13 reporting a 3.8% of PS (4.3% hallucinations, 1.1% delusions), and similar studies in Tanzania,14 South Africa15 or Spain (Catalonia)16 showing prevalences of 3.9%, 12.7% and a 11.2%, respectively (Table 1).

Table 1.

Main previous cross-sectional studies prevalences of psychotic symptoms.

Author (year)  Country/name of the study  Measure instrument  n  Prevalence of PS%  Hallucinations%  Delusions% 
Kendler et al. (1996)  United States
National Comorbidity Survey 
Computer interv/senior clinician  5877  28.0  10.7  2.2 
Van Os et al. (2000)  Netherlands
NEMESIS-1 
CIDI  7076  17.5  8.2  12.3 
Johns et al. (2004)  England
National Survey of Psychiatric Morbidity 
PSQ  8580  10.9  4.2  9.1 
Chant et al. (2006)  Australia
National Survey of Mental Health and Wellbeing 
CIDI  10,641  11.7     
Kollanagi et al. (2015)  England
Adults Psychiatric Morbidity Survey 2007 
PSQ  7403    5.15  3.84 
Mohr et al. (2008)  Czech Republic
Prague 
PSQ MINI  3244  17.9  1.7  16.7 
Ochoa et al. (2008)  Spain
ESEMeD-Catalonia Study 
CIDI  1645  11.2     
Alptekin et al. (2009)  Turkey
Izmir Mental Health Survey 
CIDI  1268  3.6     
Jenkins et al. (2010)  Tanzania
 
PSQ  899  3.9  1.1  3.9 
Leiderman et al. (2010)  Argentina
Buenos Aires 
SCL-90-R  1036    7.9  17.1 
Loch et al. (2011)  Brazil
Sao Paolo Epid. Catchment Area Study 
CIDI  1464  38.0     
Temming et al. (2011)  South Africa
South African Stress and Health Study 
CIDI  4250  12.7     
Van Nierop et al. (2012)  Netherlands
NEMESIS-2 
CIDI  6646  16.0     
Gace et al. (2012)  New Zealand
New Zealand Mental Health Survey 
CIDI  7435  7.3     
Binbay et al. (2012)  Turkey
Izmir Mental Health Survey 
  4.011  10.1     
Mamah et al. (2012)  Kenia  PRIME screen  2758  45.5     
Soosay et al. (2012)  Timor Leste  PSQ  1245  12.3     
Nuevo et al. (2012)  World Health Organization World Health Survey 52 countries  WHS
WHO 
224,254  0.8–31.4     
Van Os et al. (2013)  Meta-analysis  CIDI, PSQ, SCL-90-R, WHS, etc.  61 Cohorts  7.2     
Subramanian et al. (2014)  Singapore
Singapore Mental Health Survey 
CIDI  23,248  3.8  4.3  1.1 
Factors associated with of psychotic symptoms

Among social factors associated with PS by previous epidemiological studies are younger age, ethnic minorities, migrant status, lower pay, poorer education, unemployment, not being married, alcohol and cannabis abuse, experience of stressful events, urban upbringing and family history of mental.8,12 On the other hand, recent studies pose an “affective pathway” to early psychosis mediated by two synergistic potential risk factors: childhood trauma and “social defeat”.17 Additionally, higher risk for PS have been reported in sexual minority groups,18 bullying victims,19,20 advanced paternal (but not maternal) age at birth,21 Latino race-ethnicity22 and lower cognitive speed processing.23 Finally, many recent studies have focused on clarifying the neurodevelopmental factors associated with the expression of a continuum psychotic phenotype24–26 lending some support to the notion of a psychotic dimension in the general population.

The aims of this study are to investigate the prevalence and correlates of PS (delusions and/or hallucinations) in a representative community sample living in the province of Granada (Southern Spain) and to identify a multivariate explanatory model of potential risk correlates for PS.

MethodsDesign and sampling method

The GRANADΣP study is a cross sectional survey of general population in the province of Granada (Spain). A more detailed description of its methodology is described elsewhere.27 The study protocol was approved by the Granada University Hospitals Research Ethics Committee. Sampling was performed in a two-stage cluster sampling with stratification of the primary sampling units (PSUs) depending on whether they were rural or urban. To be able to estimate a 2% mental disorder prevalence, with ±0.8% accuracy at a 95% confidence interval, the target sample was estimated at 1176 participants. The sample was selected randomly from the National Health Service Users Database from Andalucía, which is estimated to cover 98% of the population. Interviews were conducted by fully trained psychologists who were specifically trained to administer the GRANDΣP battery of assessments and took place either in the participant's local primary health care centre or in their homes (at participant's convenience). All living participants between the ages of 18 and 80 were selected for participation in the study, divided into four age groups. Exclusion criteria were: being outside the age range, having lived in Granada province for less than a year, not being able to communicate fluently in Spanish, being too ill to be able to complete the interview, having a diagnosis of dementia or mental retardation, living in an institution (hospital, prison, etc.), having moved or not living normally at the address we had been given by the Users Database, and erroneous data from the Users Database (for example an incomplete address). Excluded participants were replaced with another individual matched for age, sex and location. Eight hundred and nine (n=809) non-institutionalized community-based participants living in the province of Granada agreed to take part in the survey, all interviews were performed between October 2011 and September 2012. Fig. 1 shows a flowchart on the cohort substitution procedure and response rates (Fig. 2).

Figure 1.

GRANADΣP study sampling procedure and response.

(0.12MB).
Figure 2.

Factors multivariately associated to psychotic symptoms.

(0.06MB).
Assessment of psychotic symptoms

The psychiatric interview section was composed of the MINI International Neuropsychiatric Interview, which generates Axis I DSM-IV, and ICD-10 diagnoses for 16 mental disorders.28 It includes a screening section for psychotic disorder that was used to ascertain PS in this study (see Table 2 that includes all actual PS items). For the purpose of this study we considered as our main outcome having at least one PS as measured on this MINI psychotic subscale, following a similar procedure to previous studies.7,9

Table 2.

Sample's sociodemographic and clinical characteristics.

Variable  % (N)/Mean (SD) 
GenderMale 48.1% (389) 
Female 51.9% (420) 
Education levelIlliterate 2.9% (23) 
Read and write 13.2% (107) 
Primary 37.8% (300) 
Secondary 26.8% (217) 
University 20.1% (160) 
Other 0.4% (3) 
Marital statusMarried/coupled 72.3% (585) 
Separate 2.5% (20) 
Widowed 4.3% (35) 
Divorced 3.9% (31) 
Single 17.1% (138) 
UrbanicityUrban 60% (486) 
Medium 29.8% (241) 
Rural 10.2% (82) 
Working statusEmployed 42.8% (346) 
Unemployed 21.2% (172) 
Retired 13.3% (107) 
Disabled 3.3% (27) 
Housewife 11.3% (92) 
Student 6.0% (49) 
Other 2.1% (17) 
Cognitive measures
Total SCIP  96.4 SD 30.5 
Learning  0.6 SD 0.17 
Working memory  0.67 SD 0.21 
Verbal fluency  15.1 SD 6.7 
Long-term memory  56.7 SD 29.1 
Visual motor skills  0.30 SD 0.17 
Personality measures
SAPAS personality disorder  3.04 SD 1.45 
Neuroticism score  2.1 SD 1.1 
Impulsivity score  −1.2 SD 1.2 
Social risk measures
GAF functionality  90.5 SD 12.7 
Child abuse (mean score)  0.15 SD 0.40 
Mean number of TLEs  1.60 SD 1.50 
Cannabis use  9.2% (74) 
Mean Suicide Risk Score  0.17 SD 0.53 
Other assessments

Sociodemographic data were collected using the indications described in previous studies.29,30 Information on psychiatric family history was gathered using a modified version of the family interview for genetic studies (FIGS)31 in which we collected data on parents and siblings. We also assessed childhood experiences of abuse in which participants answered questions about sexual, psychological and physical abuse.32 Information about stressful life events was collected using the List of Threatening Experiences Schedule, a validated 12-item questionnaire, which determines whether a person has been exposed to a highly threatening life event in the past year.33 General health was assessed using the SF12 questionnaire, which produces information about both emotional and physical health during the past four weeks.34 Functional impairment was assessed using the Global Assessment of Functioning (GAF).35 Exposure to Cannabis and other substance of abused was accomplished by using the relevant section (section K) in the MINI interview.7,9

Neuropsychological assessments were performed using the Screen for Cognitive Impairment in Psychiatry (SCIP) interview which provides scores on immediate and delayed verbal learning, working memory, verbal fluency and processing speed. The Spanish version has shown to have good test–retest reliability (0.74–0.90) and internal consistency Cronbach's alpha value of 0.73.36

We also administered the Standardized Assessment of Personality-Abbreviated Scale (SAPAS) to establish whether participants had high probability of personality disorder (HPPD) (90% or higher).37 The SAPAS is a personality disorder screening mini-interview composed of eight dichotomous questions. In addition, two personality traits (Neuroticism-anxiety and Impulsivity-Sensation Seeking) were also assessed using the appropriate sections of the Zuckerman–Kuhlman Personality Questionnaire (ZKPQ).38 An overall score of suicidal ideation was also evaluated using the appropriate section of the MINI.

Statistical analyses

Explorative assessment of data distributions, descriptive analyses including frequencies and mean values of all independent variables were calculated using SPSS. Pooled estimates of prevalence of PS were calculated with 95% confidence intervals. Chi-squared and t-Student tests were performed to explore univariate associations between PS and potential qualitative and quantitative correlates respectively. The potential confounding effects of age and gender were examined using binary logistic regression using having any PS as the main outcome variable. A multivariable model using logistic regression was also used to determine the most parsimonious explanatory model for PS. Odds ratios for quantitative independent variables represents the risk change for one-unit increase in the scale. All analyses were pondered using a weighting factor that took into account the population's structure in terms of gender, age and rurality/urbanicity index.

ResultsSample description

Out of 2338 potential participants in our census, 1176 were finally approached of whom 367 refused to take part 31% and 54 subjects were substituted for a variety of exclusion criteria reasons (see Fig. 1). Consequently, 809 (69%) were included as our final study sample (response rate=69%). Thus, the final sample was one of 809 participants. 48.1% were men and 51.9% women. Individuals were aged between 18 and 80 years whose average age was 47.16 years (SD 16.72). Most of them were married (72.3%), less than 50% had more than primary educational level and about 10% lived in a rural area. Table 2 shows a detailed summary of the sample's socio-demographic and clinical characteristics.

Eighty-three individual out of 809 were positive for the presence of any PS. Thus, the 1-month prevalence for any PS in the sample was 10.26% (95% CI 8.16–12.35). Hallucinations and delusions were analysed separately. Fifty-nine individuals reported to have delusions (7.4% (95% CI 5.55–9.15)) and 50 reported hallucinations (6.1% (4.50–7.80)). Table 3 details the individual prevalence of each PS on the MINI.

Table 3.

Positive answers to MINI psychotic symptoms subscale (prevalences/95% CI).

Question  95% CI 
1. Have you ever believed that people were spying on you, or that someone was plotting against you, or trying to hurt you?  4.44  0.30–0.59 
2. Have you ever believed that someone was reading your mind or could hear your thoughts or that you could actually read someone's mind or hear what another person was thinking?  3.46  0.22–0.47 
3. Have you ever believed that someone or some force outside of yourself put thoughts in your mind that were not your own, or made you act in a way that was not your usual self? Have you aver felt that you were possessed?  1.45  0.63–2.27 
4. Have you ever believed that your were being sent special messages through the TV, radio, or newspaper, or that a person you did not personally know was particularly interested in you?  0.99  0.30–1.68 
5. Have your relatives or friends ever consider any of your beliefs strange or inusual?  1.77  0.86–2.68 
6. Have you ever heard things other people couldn’t hear, such as voices?  1.86  0.93–2.80 
7. Have you ever had visions when you were awake or have you ever seen things other people couldn’t see?  4.88  0.34–6.37 
Prevalence of having any delusion on the MINI PS subscale  7.4  5.55–9.15 
Prevalence of having any hallucination on the MINI PS subscale  6.1  4.50–7.80 
Prevalence of having any psychotic symptom on the MINI PS subscale  10.26  8.16–12.35 
Univariate analysis

PS were not associated with gender or age in this sample. Conversely, PS did associate univariately with cannabis consumption (χ2=14.520; p=0.001), having suffered some kind of childhood abuse (χ2=19.846; p<0.001), having a positive family history of mental illness (χ2=11.514; p<0.001), having experienced stressful life event (χ2=16.441; p<0.001), being screened as a probable personality disorder by the on the SAPAS personality scale (χ2=18.225; p<0.001) and living in an intermediate area rather than on a rural or urban area (χ2=10.806; p=0.005). Significant associations were also found between having PS and higher mean scores on impulsivity (t=−4.371; p<0.001), neuroticism (t=−4.736; p<0.001), higher scores on the suicide risk MINI subscale (t=−5.175; p<0.001), TLEs (t=−6.112; p<0.001) and global SAPAS personality disorder score (t=4.880; p<0.001). PS was also associated univariately to lower educational level (t=2.012; p=0.04) and poorer physical (t=2.595; p=0.01) and emotional scores (t=5.341; p<0.001) on the respective SF12 subscales. Although all SCIP Neuropsychological scores showed poorer cognitive functions among people with PS, none of the differences were found to univariately associate with PS.

Multivariate analysis

When potential risk factors or correlates for PS were considered on a multivariate analysis, we found that PS was independently associated to a most parsimonious model including: having an increased score on the risk of suicide MINI subscale (OR=1.69; 95% CI (1.193–2.389); p=0.003), lower GAF functionality mean score (OR=0.97; 95% CI (0.953–0.988); p=0.001), having suffered any childhood abuse (OR=2.52; 95% CI (1.327–4.780); p=0.005), being a cannabis user (OR=2.12; 95% CI (1.0–4.9); p=0.047), showing a poorer performance on the SCIP working memory task (OR=0.5; 95% CI (0.01–0.244); p<0.001) and on the verbal fluency task (OR=1.1; 95% CI (1.05–1.15); p<0.001), and having higher scores on the impulsivity personality trait subscale (OR=1.45; 95% CI (1.193–1.765); p<0.001).

Discussion

The main objective of this study was to estimate the prevalence rate of PS in the province of Granada based on data from the representative sample participating in the GRANAD∑P Cross-Sectional Study. We also set for identifying correlates of PS in our area. Of the sample, 10.3% had at least one PS, 7.4% had at least one delusion and 6.1% had at least one hallucination. We also found independent associations between PS and a higher suicidal risk, poorer performance on working memory, lower verbal fluency, lower functionality, higher impulsivity and having suffered any type of abuse during the childhood.

Prevalence of psychotic symptoms

Our findings are consistent with most previous prevalence studies using an extended psychotic phenotype such as our PS outcome. Thus, we report very similar results to those obtained in the Catalonia study,16 the only other specific study on Spanish population. This is in spite that the Catalonia study used a different measuring tool such as the CIDI to categorize PS and that both Spanish regions are fairly different in economic development and cultural issues. Furthermore, our results are also congruent with average prevalences of PS reported by most of the previous European studies9,10 but higher than the average 7.2% obtained in the Van Os et al. (2013) meta-analysis that included the majority of similar reports. On the whole, our findings support the notion that a “psychosis phenotype” may exist to a varying degree across the general population. Thus, this phenotype seem to exist among many people who seem to express it mildly or sub-clinically compared to those few exhibiting more severe clinical cases, such as people suffering full-blown clinical psychosis.

We also report a prevalence of 6.1% for hallucinations, an intermediate finding among more extreme ones such as 4.2% or 10.7% found in Dutch or American studies, respectively.10,11 The prevalence of delusions in our sample was 7.4%, quite similar to 6% found in the van Os et al. meta-analysis.8 Such minor variation in prevalence figures can be accountable for by differences in random sampling and/or by the use of different diagnostic tools but, globally, seem to convey a solid message in favour of a continuum between clinical and subclinical cases4 when PS are explored in general population. Our finding that delusions seem to be more prevalent than hallucinations also streams in with most previous reports with few exceptions.9–11

Childhood abuse and PS

Despite the associations between child trauma and psychosis is not entirely consistent in the light of previous systematic reviews,7,39,40 there is a large body of literature, during the last few years, showing a robust association between childhood maltreatment and development of adult psychosis.41,42 Maltreatment not only influences the child's psychological wellbeing but also inhibits domains of social development that, in turn, have been found to predate the onset of psychosis.42,43 Furthermore, some studies have demonstrated a dose–response association between childhood maltreatment and psychosis in both prospective and cross-sectional studies.41,42 In addition to this, synergistic pathways of risk have recently been defined showing that childhood trauma, bullying and experience of discrimination do associate with PS.19 Our finding that child abuse is a robust risk correlates for PS favours the view that child trauma may indeed increase risk for psychosis. It is also important to highlight that cannabis use joined to childhood maltreatment has also been defined as a synergic factor too that impact on PS risk, which is compatible with our univariate findings of excess risk for PS among cannabis users.44

Cannabis use and PS

We found cannabis used to be independently associated to PS, which replicates findings from a recent meta-analysis looking at similar population based studies.7 Cannabis use is a well-established risk factor for clinical psychosis.45,46 Moreover, randomized experimental studies have demonstrated that cannabis used-induced biochemical effects in the brain47 and genetic liability for schizophrenia may interact increasing the risk for PS.3,48 Moreover, a study shows that delta-9-tetrahidrocannabinol, cannabis main psychotropic component, causes transitory PS in healthy volunteers and triggers an exaggerated psychotic response in individuals with genetic risk for psychotic disorder. Overall, there is also evidence that the influence of cannabis on PS may be mediated through effects on dopamine processing in certain brain areas.49,50

Impulsivity and PS

Patients with clinical psychosis often display behavioural problems that suggest impaired impulse control.51 To our Knowledge, there are no previous studies reporting Personality Disorders measured by SAPAS questionnaire in individuals with PS and there is a relative scarcity of epidemiological studies looking at personality traits into PS.52 Neuroticism has been reported as linked to PS in other study9 and it is plausible that other personality traits may also represent a potential psychological risk factor for PS. Indeed we found that neuroticism (univariately) and impulsivity (multivariately) associate with PS in our sample. This finding could be explained by common genetic predisposition, common psychological components and/or common environmental risk factors between both personality traits and PS.53,54 In our sample, individuals with PS report higher levels of impulsivity, something that has been reported earlier in an African-American general population sample where impulsivity was measured with the Barratt Impulsiveness Scale (BIS-11).52 Higher impulsivity has also been found among subject considered as ultra-high-risk subjects for psychosis.53 This association has been posed to suggest a possibly altered capacity for conflict processing, which, in turn, has been proposed to stem from functional abnormalities at the Anterior Cingulate Cortex.53

Suicide risk and PS

Clinical psychosis such as schizophrenia is the second most frequent psychiatric disorder among people who commit suicide.55 Our finding that PS is associated with an increased score on the suicide risk MINI subscale is congruent with a notion of higher suicide risk among people with PS and also replicates previous findings in similar studies.14,56–58 Although, this association had been posed59 as a confounder for the association between personality disorder or impulsivity with both PS and suicide risk. However this explanation would be ruled out in our study provided that we included such variables in our multivariate model, suggesting that the association maybe mediated by other co-factors.58 In sum, we consider that our finding here supports the idea that assessment and management of suicide risk in individuals reporting PS may be relevant for suicide prevention.

Cognitive deficits and PS

Cognitive deficits are generally considered a core feature of psychotic disorders. A recent meta-analysis has documented impairment in psychotic patients on a range of cognitive functions, including verbal memory and fluency, executive functions, working memory, and sustained attention.60 Our findings replicate some of these findings, such as poorer verbal fluency and working memory, when community-dwelling subjects with PS, rather than psychotic patients, are compared with controls for PS. We interpret this finding as supportive of the concept of continuum PS phenotype where patients with more severe psychotic disorder exhibit a larger degree of cognitive impairment, mainly frontal, that is more moderately evident in subclinical cases with PS.61 A recent Spanish 5-year-follow-up study of first-episode psychosis patients has shown that working memory impairment is associated to negative PS and poor functional outcomes, explaining that the association between these cognitive deficits (verbal fluency and working memory) and PS/Disfunctionality is mediated by negative PS.62 Our finding on working memory and verbal fluency and PS also replicates similar reports.63,64 A plausible common psychological process explaining poorer working memory in PS is that deficits in working memory are linked to the “jumping to conclusions” bias which is typical for psychosis, particularly abnormal belief formation.65 A potential common genetic link for both PS and poor working memory has been suggested as a 22q11.2 deletion syndrome (22q11DS).66 Targeting cognitive symptoms in people with PS can improve prevention of such subclinical cases and maybe their progress to clinical psychosis.

GAF and PS

Many studies have demonstrated that people with PS show a diminished global functionality.15,21 Our finding that lower functionality is associated with PS add support to PS as a valid outcome provided that both, clinical and non-clinical cases of psychosis are elicitable in the community and all seem to have some functional impact, as could be expected in a continuous phenotype. Furthermore, a study comprising three meta-analyses shows that functionality is impaired not only in psychotic cases but also in those at high-risk state.67

Strengths and limitations

Strengths of the study are the relative good sample size and representativeness of the sample. This is one of the few existing community-based studies developing a formal assessment of cognitive functions and personality traits in a broad non-clinical sample. The main limitation is the cross-sectional design that cannot define cause-effect associations and the non-clinical screening characterization of PS. However, all interviewers were clinical psychologists with specific training on PS detection, which may have improved the quality of PS eliciting as compared to other general population studies typically using lay interviewers. Secondary limitations of representativeness are that individuals who live in institutions or were hospitalized were not included in the survey.

Conclusions

The prevalence of PS in the Andalusian community is similar to that reported among comparable European populations and is clearly higher than that of psychotic disorders. This may indicate that an extended subclinical psychotic phenotype can be detectable in the general population. PS associates with social adversity and environmental factors, cognitive deficits, dysfunctionality and a higher suicide risk. Clinical targeting these potential risk correlates among people with PS may prove of some assistance in the effort of preventing transition from subclinical non-cases to clinical psychotic states.

Funding

The study was partially funded by grants from Consejería de Salud, Junta de AndalucíaPI322-2009 and Consejería de Innovación, Proyecto de ExcelenciaCTS-2010-6682.

Conflict of interest

The authors declare no conflicts of interest.

References
[1]
ISSN 0214-4220
[2]
J. Van Os, M. Hanssen.
Strauss (1969) revisited: a psychosis continuum in the general population?.
Schizophr Res, 45 (2000), pp. 11-20
[3]
G. Dodgson, S. Gordon.
Avoiding false negatives: are some auditory hallucinations an evolved design flaw?.
Behav Cogn Psychother, 37 (2009), pp. 325-334
[4]
J. Van Os, J. Kenis, B. Rutten.
The environment and schizophrenia.
Nature, 468 (2010), pp. 203-212
[5]
Diagnostic and statistical manual of mental disorders: DSM-V American Psychiatric Association.
American Psychiatric Pub., (2013), pp. 87-89
Section 2
[6]
D.V. Sheehan, Y. Lekrubier, K. Hartnet Sheehan, J. Janavs.
The validity of the Mini International Neuropsychiatric Interview (MINI) according to the SCID-P and its reliability.
Eur Psychiatry, 12 (1997), pp. 232-241
[7]
H. Verdoux, M. Husky, M. Tournier, F. Sorbara, J.D. Swendsen.
Social environments and daily life occurrence of psychotic symptoms.
Soc Psychiatry Psychiatr Epidemiol, 38 (2003), pp. 654-661
[8]
J. Van Os, R.J. Linscott, I. Myin-Germeys, P. Delespaul, L. Krabbendam.
An updated and conservative systematic review and meta-analysis of epidemiological evidence on psychotic experiences in children and adults: on the pathway from proneness to persistence to dimensional expression across mental disorders.
Psychol Med, 43 (2013), pp. 1133-1149
[9]
M. Van Nierop, J. Van Os, N. Gunther.
Phenotypically continuous with clinical psychosis. Discontinuous in need for care: evidence for an extended psychosis phenotype.
Schizophr Bull, 38 (2012), pp. 231-238
[10]
L.C. Johns, M. Cannon, N. Singleton, R.M. Murray, M. Farrell, T. Brugha, et al.
Prevalence and correlates of self-reported psychotic symptoms in the British population.
Br J Psychiatry, 185 (2004), pp. 298-305
[11]
C.I. Cohen, L. Marino.
Racial and ethnic differences in the prevalence of psychotic symptoms in the general population.
Psychiatr Serv (Washington, DC), 64 (2013), pp. 1103-1109
[12]
R. Nuevo, S. Chatterji, E. Verdes, N. Naidoo, C. Arango, J.L. Ayuso-Mateos.
The continuum of psychotic symptoms in the general population: a cross-national study.
Schizophr Bull, 38 (2010), pp. 475-485
[13]
A. Subramaniam, E. Abdin, J.A. Vaingankar, S. Verma, S.A. Chong.
Latent structure of psychosis in the general population: results from the Singapore mental health study.
Psychol Med, 44 (2013), pp. 51-60
[14]
R. Jenkins, J. Mbatia, N. Singleton, B. White.
Prevalence of psychotic symptoms and their risk factors in urban Tanzania.
Int J Environ Res Public Health, 7 (2010), pp. 2514-2525
[15]
H. Temmingh, D.J. Stein, S. Seedat, D.R. Williams.
The prevalence and correlates of hallucinations in a general population sample: findings from the South African stress and health study.
Afr J Psychiatry, 14 (2011), pp. 211
[16]
S. Ochoa, J.M. Haro, J.V. Torres, A. Pinto-Meza, C. Palacín, M. Bernal, et al.
What is the relative importance of self reported psychotic symptoms in epidemiological studies? Results from the ESEMeD—Catalonia study.
Schizophr Res, 102 (2008), pp. 261-269
[17]
M. Van Nierop, J. Van Os, N. Gunther.
Does social defeat mediate the association between childhood trauma and psychosis? Evidence from the NEMESIS-2 study.
Acta Psychiatr Scand, 129 (2014), pp. 467-476
[18]
M.J. Gevonden, J.P. Selten, I. Myin-Germeys, R. Graaf, M. ten Have, S. van Dorsselaer, et al.
Sexual minority status and psychotic symptoms: findings from the Netherlands mental health survey and incidence studies (NEMESIS).
Psychol Med, 44 (2013), pp. 421-433
[19]
G. Catone, S. Marwaha, E. Kuipers, B. Lennox, D. Freeman, P. Bebbington, et al.
Bullying victimisation and risk of psychotic phenomena: analyses of British National Survey Data.
Lancet Psychiatry, 2 (2015), pp. 618-624
[20]
K. Sitko, R.P. Bentall, M. Shevlin, N. O'Sullivan, W. Sellwood.
Associations between specific psychotic symptoms and specific childhood adversities are mediated by attachment styles: an analysis of the national comorbidity survey.
Psychiatry Res, 217 (2014), pp. 202-209
[21]
J. Foutz, B. Mezuk.
Advanced paternal age and risk of psychotic-like symptoms in adult offspring.
Schizophr Res, 165 (2015), pp. 123-127
[22]
C.I. Cohen, M.P.H. Leslie Marino.
Racial and ethnic differences in the prevalence of psychotic symptoms in the general population.
Psychiatr Serv, 11 (2013), pp. 1103-1109
[23]
W. Rössler, M. Müller.
Association between processing speed and subclinical psychotic symptoms in the general population: focusing on sex differences.
Schizophr Res, 166 (2015), pp. 316-321
[24]
M. Drakesmith, A. Dutt, L. Fonville, A. Reichenberg, J. Evans, G. Lewis, et al.
Mediation of developmental risk factors for psychosis by white matter microstructure in young adults with psychotic experiences.
JAMA Psychiatry, 73 (2016), pp. 396-406
[25]
L.K.L. Oestreich, N.G. Mifsud, J.M. Ford, B.J. Roach, D.H. Mathalon, T.J. Whitford.
Cortical suppression to delayed self-initiated auditory stimuli in schizotypy: neurophysiological evidence for a continuum of psychosis.
Clin EEG Neurosci, 47 (2016), pp. 3-10
[26]
C. Döring, M. Müller, F. Hagenmuller, V. Ajdacic-Gross, H. Haker, W. Kawohl, et al.
Mismatch negativity: alterations in adults from the general population who report subclinical psychotic symptoms.
Eur Psychiatry, 34 (2016), pp. 9-16
[27]
J.A. Cervilla, I. Ruiz, M. Rodríguez-Barranco, M. Rivera, I. Ibáñez-Casas, E. Molina, et al.
Protocol and methodology of the epidemiological mental health study in Andalusia: PISMA-ep.
Rev Psiquiatr Salud Ment, 9 (2016), pp. 185-194
[28]
D.V. Sheehan, Y. Lecrubier, K. Harnett-Sheehan, P. Amorim, J. Janavs, E. Weiller, et al.
The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10.
J Clin Psychiatry, 59 (1998), pp. 22-33
[29]
A. Barona, C.R. Reynolds, R. Chastain.
A demographically based index premorbid intelligence for the WAIS-R.
J Consult Clin Psychol, 52 (1984), pp. 887
[30]
A. Bilbao, N. Seisdedos.
Eficacia de una fórmula de estimación de la inteligencia premórbida en la población española.
Rev Neurol, 38 (2004), pp. 431-434
[31]
NIMH Repository and Genomics Resource.
Family interview for genetic studies 4.0/BP.
[32]
L.A. Fink, D. Bernstein, L. Handelsman, J. Foote, M. Lovejoy.
Initial reliability and validity of the childhood trauma interview: a new multidimensional measure of childhood interpersonal trauma.
Am J Psychiatry, 152 (1995), pp. 1329-1335
[33]
T. Brugha, P. Bebbington, C. Tennant, J. Hurry.
The list of threatening experiences: a subset of 12 life event categories with considerable long-term contextual threat.
Psychol Med, 15 (1985), pp. 189-194
[34]
B. Gandek, J.E. Ware, N.K. Aaronson, G. Apolone, J.B. Bjorner, J. Brazier, et al.
Cross-validation of item selection and scoring for the SF-12 Health Survey in nine countries: results from the IQOLA Project. International Quality of Life Assessment.
J Clin Epidemiol, 51 (1998), pp. 1171-1178
[35]
American Psychiatric Association.
Diagnostic and statistical manual of mental disorders, fourth edition, text revision (DSM-IV-TR).
American Psychiatric Association, (2000),
[36]
O. Pino, G. Guilera, E. Rojo, J. Gómez-Benito, M. Bernardo, B. Crespo-Facorro, The Spanish Working Group in Cognitive Function, et al.
Spanish version of the Screen for Cognitive Impairment in Psychiatry (SCIP-S): psychometric properties of a brief scale for cognitive evaluation in schizophrenia.
Schizophr Res, 99 (2008), pp. 139-148
[37]
P. Moran, M. Leese, T. Lee, P. Walters, G. Thornicroft, A. Mann.
Standardised Assessment of Personality – Abbreviated Scale (SAPAS): preliminary validation of a brief screen for personality disorder.
Br J Psychiatry, 183 (2003), pp. 228-232
[38]
M. Zuckerman.
Zuckerman–Kuhlman Personality Questionnaire (ZKPQ): an alternative five-factorial model.
Big five assessment, pp. 377-396
[39]
J. Read, J. van Os, A.P. Morrison, C. Ross.
A. Childhood trauma, psychosis and schizophrenia: a literature review with theoretical and clinical implications.
Acta Psychiatr Scand, 112 (2005), pp. 330-350
[40]
S. Bendall, H.J. Jackson, C.A. Hulbert, P.D. McGorry.
Childhood trauma and psychotic disorders: a systematic, critical review of the evidence.
Schizophr Bull, 34 (2008), pp. 568-579
[41]
M. Van Nierop, T. Lataster, F. Smeets, N. Gunther, C. van Zelst, R. de Graaf, et al.
Psychopathological mechanisms linking childhood traumatic experiences to risk of psychotic symptoms: analysis of a large, representative population-based sample.
Schizophr Bull, 40 (2014), pp. 130
[42]
L. Arseneault, M. Cannon, H.L. Fisher, G. Polanczyk, T.E. Moffitt, A. Caspi.
Childhood trauma and children's emerging psychotic symptoms: a genetically sensitive longitudinal cohort study.
Am J Psychiatry, 168 (2011), pp. 65-72
[43]
M.L. Barrigón, F.J. Diaz, M. Gurpegui, M. Ferrin, J.A. Cervilla, M. Ruiz-Veguilla, et al.
Childhood trauma as a risk factor for psychosis: a sib-pair study.
J Psychiatr Res, 70 (2015), pp. 130-136
[44]
M. Konings, N. Stefanis, R. Kuepper, R. de Graaf, M. ten Have, J. van Os, et al.
Replication in two independent population-based samples that childhood maltreatment and cannabis use synergistically impact on psychosis risk.
Psychol Med, 42 (2011), pp. 149-159
[45]
M. Ruiz-Veguilla, M.L. Barrigón, L. Hernández, J.L. Rubio, M. Gurpegui, F. Sarramea, et al.
Dose–response effect between cannabis use and psychosis liability in a non-clinical population: evidence from a snowball sample.
J Psychiatr Res, 47 (2013), pp. 1036-1043
[46]
T. Kraan, E. Velthorst, L. Koenders, K. Zwaart, H.K. Ising, D. van den Berg, et al.
Cannabis use and transition to psychosis in individuals at ultra-high risk: review and meta-analysis.
Psychol Med, 46 (2016), pp. 673-681
[47]
D.M. Fergusson.
Cannabis and psychosis.
[48]
L. Gómez Pérez, A.M. Santacana, D. Bergé Baquero, V. Pérez-Solá.
Reasons and subjective effects of cannabis use among people with psychotic disorders: a systematic review.
Actas españolas de psiquiatría, 42 (2014), pp. 83
[49]
P.D. Morrison, V. Zois, D.A. McKeown, T.D. Lee, D.W. Holt, J.F. Powell, et al.
The acute effects of synthetic intravenous Δ9-tetrahydrocannabinol on psychosis, mood and cognitive functioning.
Psychol Med, 39 (2009), pp. 1607-1616
[50]
D.C. D'Souza, W.M. Abi-Saabce, S. Madonick, K. Forselius-Bielen, A. Doersch, G. Braleya, et al.
Delta-9-tetrahydrocannabinol effects in schizophrenia: implications for cognition, psychosis, and addiction.
Biol Psychiatry, 57 (2005), pp. 594-608
[51]
K.A. Nolan, D. D’Angelo, M.J. Hoptman.
Self-report and laboratory measures of impulsivity in patients with schizophrenia or schizoaffective disorder and healthy controls.
Psychiatry Res, 187 (2011), pp. 301-303
[52]
M.T. Compton, N.J. Kaslow.
Self-reported psychotic symptoms predict impulsivity among African-American patients in an urban non-psychiatric medical setting.
Psychiatry Res, 135 (2005), pp. 35-44
[53]
T.Y. Lee, S.N. Kim, J.H. Jang, G. Shim, W. Jun, N. Youn, et al.
Neural correlate of impulsivity in subjects at ultra-high risk for psychosis.
Prog Neuro-Psychopharmacol Biol Psychiatry, 45 (2013), pp. 165-169
[54]
W.R. Lovallo.
Early life adversity reduces stress reactivity and enhances impulsive behavior: implications for health behaviors.
Int J Psychophysiol, 90 (2013), pp. 8-16
[55]
W.S. Fenton, T.H. McGlashan, B.J. Victor, C.R. Blyler.
Symptoms, subtype, and suicidality in patients with schizophrenia spectrum disorders.
Am J Psychiatry, 154 (1997), pp. 199-204
[56]
J.E. DeVylder, E.P. Lukens, B.G. Link, J.A. Lieberman.
Suicidal ideation and suicide attempts among adults with psychotic experiences.
JAMA Psychiatry, 72 (2015), pp. 219-225
[57]
A. Koyanagi, A. Stickley, J.M. Haro.
Subclinical psychosis and suicidal behavior in England: findings from the 2007 adult psychiatric morbidity survey.
Schizophr Res, 168 (2015), pp. 62-67
[58]
J.E. DeVylder, D.R. Jahn, T. Doherty, C.S. Wilson, H.C. Wilcox, J. Schiffman, et al.
Social and psychological contributions to the co-occurrence of sub-threshold psychotic experiences and suicidal behavior.
Soc Psychiatry Psychiatr Epidemiol, 50 (2015), pp. 1819-1830
[59]
A. McGirr, G. Turecki.
What is specific to suicide in schizophrenia disorder? Demographic, clinical and behavioural dimensions.
Schizophr Res, 98 (2008), pp. 217-224
[60]
R.I. Mesholam-Gately, A.J. Giuliano, K.P. Goff, S.V. Faraone, L.J. Seidman.
Neurocognition in first-episode schizophrenia: a meta-analytic review.
Neuropsychology, 23 (2009), pp. 315-336
[61]
I. Ibanez-Casas, J.A. Cervilla.
Neuropsychological research in delusional disorder: a comprehensive review.
Psychopathology, 45 (2012), pp. 78-95
[62]
I. González-Ortega, V. de los Mozos, E. Echeburúa, M. Mezo, A. Besga, S. Ruiz de Azúa, et al.
Working memory as a predictor of negative symptoms and functional outcome in first episode psychosis.
Psychiatry Res, 206 (2013), pp. 8-16
[63]
M.R. Broome, F. Day, I. Valli, A. Valmaggia, L.C. Johns, O. Howes, et al.
Delusional ideation, manic symptomatology and working memory in a cohort at clinical high-risk for psychosis: a longitudinal study.
Eur Psychiatry, 27 (2012), pp. 258-263
[64]
T.B. Ziermans.
Working memory capacity and psychotic-like experiences in a general population sample of adolescents and young adults.
Front Psychiatry, 4 (2013), pp. 161
[65]
M.R. Broome, L.C. Johns, I. Valli, J. Woolley, P. Tabraham, C. Brett, et al.
Delusion formation and reasoning biases in those at clinical high risk for psychosis.
Br J Psychiatry, 191 (2007), pp. s42
[66]
C.A. Montojo, A. Ibrahim, K.H. Karlsgodt, C. Chowa, A.E. Hilton, R.K. Jonasa, et al.
Disrupted working memory circuitry and psychotic symptoms in 22q11.2 deletion syndrome.
NeuroImage Clin, 4 (2014), pp. 392-402
[67]
P. Fusar-Poli, M. Rocchetti, A. Sardella, A. Avila, M. Brandizzi, E. Caverzasi, et al.
Disorder, not just state of risk: meta-analysis of functioning and quality of life in people at high risk of psychosis.
Br J Psychiatry, 207 (2015), pp. 198-206
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